I will be glad if you find here any idea how to make your flat facade better!
As you see the architect (or the time) work here with just one color plaster and the rest is concrete.
And here we see more materials and colors used to create monumentality - different plasters. more glass, metal and even bricks.
What about this facade? maybe this is the best example here, beecause the solution for the facades is included in the architectural project.
What are you thinking about the green in the center?